The present application relates to the field of iron and hydrogen sulfide removal. In particular, the present invention relates to an automated system for controlling the air pressure in an aeration tank.
The presence of iron and hydrogen sulfide in well water can result in undesirable tastes, smells, stains, and corrosion. To prevent the negative effects of iron and hydrogen sulfide in water, the contaminants are typically removed from the well water by a filtration system. The filtration system includes an aeration tank and a filtration tank that remove the iron and hydrogen sulfide from the water through oxidation and filtration. The iron and hydrogen sulfide are oxidized in the aeration tank by a head of oxygen-rich air that is maintained in the aeration tank by an air pump. As air is pumped into the aeration tank, the air pressure in the tank steadily increases and must be released to prevent overpressure in the aeration tank. The pressure is released through a bleed passage connected to the aeration tank. After the iron and hydrogen sulfide have been oxidized in the aeration tank, the water is transported to the filtration tank where the iron and hydrogen sulfide are removed from the water.
An automated removal control system currently in use employs a timer to control the introduction of air into the aeration tank according to a predetermined time cycle. Because this system is controlled solely as a function of time and is unrelated to the condition of the aeration tank, the level of oxygen in the aeration tank is not monitored and the system may not run often enough. Power is consumed unnecessarily when the air pump and bleed passage are activated even though there is a sufficient supply of air in the aeration tank. When the system fails to run and there is an insufficient amount of air in the aeration tank, the iron and hydrogen sulfide in the water are not properly oxidized and cannot be effectively filtered from the water.